1st gen TPU is 92 TOPS and an OP is an 8bit int multiplication.
Lets cut this crap of comparing apples and oranges. Please take a look at:
https://arxiv.org/abs/1704.04760

The actual comparison (not apples and oranges stuff you mention) you can see in Table 6 where typical ML application are compared (MLP and CNN).
Factor between first gen TPU and K80 (that is 3-5x faster for ML compared to 1080) is between 15 and 60 averaging around 25x.